Hansa Biopharma has presented compelling five-year follow-up data demonstrating the sustained efficacy of imlifidase in enabling kidney transplantation for highly sensitized patients, while also advancing the drug's potential in autoimmune disease treatment.
Long-Term Transplant Success Validates Treatment Approach
The Swedish biopharmaceutical company presented results from its extended pooled analysis, including data from the 17-HMedIdeS-14 study, at the 2025 International Transplant Congress of the European Society for Organ Transplantation in London. The five-year data showed remarkable durability, with patient survival rates of 90% and death-censored graft survival of 82%.
"This study demonstrated for the first time that HLA-incompatible transplantation following desensitization with imlifidase is a viable option for patients who need it, with long term benefit comparable to standard kidney transplants, providing a life changing alternative to remaining on dialysis," said Hitto Kaufmann, Chief R&D Officer at Hansa Biopharma.
The analysis revealed that three deaths occurred between six months and one year post-transplant, with outcomes remaining stable thereafter. At five years, the mean estimated glomerular filtration rate (eGFR) was 50 mL/min/m², indicating preserved kidney function. This compares favorably to typical kidney transplant recipients, who generally show mean eGFR between 40-60 mL/min per 1.73 m² at three years post-transplant, with continued decline at five years.
Addressing Critical Unmet Need in Transplantation
Highly sensitized patients represent a particularly challenging population in kidney transplantation, comprising approximately 10-15% of patients on transplant waiting lists across the U.S. and Europe. These patients have pre-formed donor-specific antibodies (DSAs) with broad reactivity against human leukocyte antigens (HLAs), making it extremely difficult to find compatible donor organs.
The complexity of their immunological profile means highly sensitized patients spend significantly longer on transplant waiting lists, with evidence showing this extended waiting time correlates with increased mortality risk. The presence of DSAs can cause tissue damage and potentially lead to transplant rejection, traditionally limiting these patients' access to transplantation.
Imlifidase, marketed under the trade name IDEFIRIX in Europe, is an antibody-cleaving enzyme that specifically targets and cleaves immunoglobulin G (IgG) antibodies. The drug has a rapid onset of action, cleaving IgG antibodies and inhibiting their activity within hours of administration, creating a window of opportunity for transplantation before the body synthesizes new antibodies.
Expanding Therapeutic Applications
Beyond transplantation, Hansa Biopharma is exploring imlifidase's potential in autoimmune diseases. The company presented data from its Phase 2 study in Guillain-Barré Syndrome (GBS) at the 2025 Peripheral Nerve Society Annual Meeting in Edinburgh.
The 15-HMedIdeS-09 study evaluated a single dose of imlifidase (0.25 mg/kg) in 30 adult GBS patients in combination with standard-of-care intravenous immunoglobulin (IVIg) therapy. The treatment was considered safe and well-tolerated when administered prior to standard care.
"We know that IgG is a key driver of inflammatory attacks on peripheral nerves and has been clinically linked to the severity and progression of GBS, and that there is a clear and urgent need for new and faster treatment options in GBS," Kaufmann explained.
GBS is a rare, acute inflammatory disease of the peripheral nervous system affecting 1-2 in 100,000 people annually. The condition can lead to severe paralysis, with approximately 25% of patients requiring mechanical ventilation and 20% unable to walk after six months. Even with current standard treatments, GBS proves fatal in 3-7% of cases.
Comprehensive Clinical Development Program
The 17-HMedIdeS-14 study represents part of Hansa's broader HMedIdeS clinical program for imlifidase, which includes four global Phase 2 trials, one U.S. open-label Phase 3 trial (ConfIdeS), and a post-authorization efficacy and safety study in Europe.
The five-year extended pooled analysis continues previous three-year data published in the American Journal of Transplantation, providing long-term evidence of imlifidase's sustained benefit in this challenging patient population.
Imlifidase received conditional marketing approval in Europe through the European Medicines Agency's PRIME program, which supports medicines offering major therapeutic advantages over existing treatments or benefiting patients without treatment options. The approval is specifically for desensitization treatment of highly sensitized adult kidney transplant patients with positive crossmatch against available deceased donors.
Future Development Pipeline
Hansa Biopharma's pipeline extends beyond imlifidase to include HNSA-5487, a next-generation IgG cleaving molecule with redosing potential. This compound is advancing into clinical phases focusing on myasthenia gravis and potentially other neuro-autoimmune diseases.
The company's proprietary IgG-cleaving enzyme technology platform positions it to address serious unmet medical needs across autoimmune diseases, gene therapy, and transplantation. With operations in Europe and the U.S., Hansa continues to advance its mission of developing life-saving treatments for patients with rare immunological conditions.
